Eruption of Black Motor Oil: The Fascinating Natural Wonder of Ol Doinyo Lengai Volcano in Africa

The Ol Doinyo Lengai volcano in Africa is one of the most unique and fascinating natural wonders on Earth. Unlike most volcanoes that erupt red-hot silicate lava, this one spews black, viscous lava that flows like motor oil. Located in northern Tanzania on the East African Rift, it is the only known volcano to erupt carbon-based lava known as natrocarbonatite lava.

Despite its relatively low silicate content, Ol Doinyo Lengai’s lava remains liquid at temperatures as low as 540 degrees Celsius due to its high carbonate mineral content. This makes the lava extremely viscous and gives it the appearance of spewing black motor oil during eruptions. Surprisingly, the lava can still erupt violently, producing streams of liquid lava filled with dissolved CO2 and other gases that bubble like carbonated water.

This tectonically active giant crack in the African plate is home to two vents, but only the northern vent erupts. The most recent eruption began in April 2017 and was ongoing as of March 2024. A team of volcanologists studying gas samples from the volcano in 2009 found that the composition of the gases was similar to those spewed from mid-ocean ridges, suggesting that the carbon-based lava is produced by minerals melting in the upper mantle.

Ol Doinyo Lengai is just one of many geological wonders in the East African Rift region, which is slowly moving apart and could eventually tear Africa in half, creating a new ocean. In addition to Ol Doinyo Lengai, this region is responsible for creating other towering mountains such as Mount Kilimanjaro and Mount Kenya.